Why Do Flowers Smell?


While out walking the other day, I was overcome by the smell of giant hogweed and was surprised how many flies were flying around it. This made me wonder why they were attracted to the smell.

Flowers use a combination of chemicals to emit a smell. Some flowers use smell to attract insects to pollinate, while others use smell to repel insects. Flowers are used in cooking, as essential oils, and as air fresheners.

If you want to find out more, then there is some great information below.

One of the first aspects of a flower you may notice is the beautiful smell they give off. These smells are not for us, however. The smells are used to attract insects to pollinate while also warning other insects away.

Most plants have a distinctive smell that allows you to identify them for one another. Some are pleasant to our noses, such as the beautiful, sweet smell of roses or honeysuckle to the sharp, refreshing smell of mint. However, others, such as hogweed, are not pleasant at all.

Smells are made as a result of a combination of chemical substances. The plants synthesize the chemicals by using a lot of energy. Therefore it should be no surprise that flowers use their smell for many different things from defense to pollination. However, many plants are used by us in cooking due to their strong smells due to these chemicals.

Aromatic Families

There are a small number of plant families where a large proportion of their species have aromatic plants such as flowers, roots, stems, or foliage. Still, many individual species are aromatic.

Mint has several species in its family, and although they all smell much like we expect them to of mint, they all smell slightly different. All mint species contain menthol, an ingredient that we use in many of our cold and cough medicines. Menthol is why all species of mint smell similar.

The different types of mint come from the other substances and chemicals that they create, making some better for certain uses.

Daisies contain several different types in their family, including many different scented plants. Pineapple weed smells similar to pineapples, while other members of the daisy family include chamomile, wormwood, and mayweed.

The carrot family includes several different smelling plants as well. Wild carrot, hemlock, parsley, and chervil are all part of the same family.

Essential Oils

The scents of many flowers and plants are also used in essential oils. These are made up of the scented chemicals produced by plants. The oils are secreted by special cells in the petals, leaves, or stems.

The oils accumulate close to the surface, releasing their scent continuously in some plants, whereas others only release their scent if the plant is bruised or damaged.

Mint is a popular essential oil where the oil is close to the surface and is one reason why the smell is so pungent and strong. Lavender and thyme oil evaporates slowly, leaving the smell hanging in the air for some time. Evaporation of the oil allows the plants to cool, helping the plant avoid water loss from its leaves.

St. Johns Wort has many oil glands in its leaves, and the oil can be seen easily.

Wildwood garlic smell only when their leaves are bruised or crushed. If you have ever walked through a patch of wildwood garlic, then you will know the smell they emit.

Chemical Messages

Although many plants smell nice and great that we can use them as essential oils, this is not the main reason for releasing these chemicals.

The smells act as chemical messages between themselves and insects or animals. The messages may be used to attract or repel certain species. The messages are even directed at certain species of animal.

Although we can smell plants and flowers, these messages are not often intended for other mammals or us. Some poisonous plants such as hemlock or hellebore use their smell to stop animals from eating them.

Insects are the intended recipient of the smells from a plant or flower. Insects have an excellent sense of smell and can find the location of a flower from their smell. Insects are used for pollination, and the smell allows the flower to reproduce, which is their main aim.

The smell is effective over long distances and works much better in attracting insects than the plant’s color. The smell can be used to attract daytime insects and nocturnal insects, such as moths, allowing them to pollinate at night. The smell also allows plants that grow in the shade also to attract insects.

Many plants do not rely on flowers at all as a means of attracting insects, relying on their scent to attract pollinators. Many plants that do not rely on flowers to attract insects are white

Butterflies and moths have such highly developed senses of smell that they can detect a single flower from more than 1km away. The increase in concentration as they get closer allows them to find the flower with ease.

Selective Smells

Different plants use different combinations of chemicals depending on the pollinating insect they are trying to attract. Flies are attracted to decaying flesh as larvae, and plants such as hogweed imitate this smell to attract them. Flies may use the plants to lay their eggs as they may still be convinced that what they have landed on is a dead animal.

While plants such as hogweed give off a decaying flesh smell, other plants give off a sickly sweet smell that attracts insects attracted to nectar. Bluebells, roses, and violets all attract butterflies that are attracted to the smell.

Caterpillars feed on plants that they find attractive. By feeding on them, they store some of the plant’s scent in their bodies. Once they have gone through the pupa stage, metamorphizing into butterflies, they release some of these scents’ traces, which allows them to attract a mate.

Warnings

Although many smells released attract different types of insects, some smells released warn insects away. Insects that can be harmful to the plant are often warned away by the smell, advising them to stay away from poisonous plants.

The poisons released act as a natural insecticide, with the poisons being scented. Wormwood can be used to keep flies out of a room and keep moths out of clothes due to their scent.

Some plant chemicals, such as pyrethrum, is used in many commercial insecticides.

Air Fresheners

One of the ways that we use plants is as air fresheners. History has shown that we have used plants and herbs as air fresheners, strewn around houses on floors. Mints, rushes, and sweet flag, one of the oldest known plants, can all be used as air fresheners.

Many commercial air fresheners still use plants as their basis, with essential oils being used. Pine has been used for more than a century, with pine cones being used historically as natural air fresheners, placed around the house and in clothes.

Kitchen Herbs

Many plants are used every day for their aroma as herbs during cooking. Herbs were originally added to food to break up the monotony of eating the same dish every night, also improving food that may have gone slightly off.

Many herbs have been cultivated for centuries for food, spreading from herb gardens into the wild. Fennel, coriander, and parsley are used every day in cooking.

Bryan Harding

Bryan has spent his whole life around animals. While loving all animals, Bryan is especially fond of mammals and has studied and worked with them around the world. Not only does Bryan share his knowledge and experience with our readers, but he also serves as owner, editor, and publisher of North American Mammals.

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